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United States Patent | 5,751,695 |
Ohashi | May 12, 1998 |
An ATM cell flow control apparatus includes interface sections for terminating transmission lines of two systems which constitute a redundant structure and to which identical cell sequences are supplied. Each interface section includes a cell synchronization section, a cell buffer, a policing section, and a delay control section. The cell synchronization section performs cell synchronization control of an input cell sequence and outputs the sequence in units of cells. The cell buffer performs delay adjustment of each cell output from the cell synchronization section. The policing section detects the cell interval between cells output from the cell buffer, and discards cells having a detected cell interval shorter than a predetermined cell interval. The delay control section detects the phase difference between a cell output from the cell buffer of a self-system and a cell output from the cell buffer of the other system, and controls the cell buffer in accordance with the detected phase difference.
Inventors: | Ohashi; Satoshi (Tokyo, JP) |
Assignee: | NEC Corporation (Tokyo, JP) |
Appl. No.: | 712837 |
Filed: | September 12, 1996 |
Sep 13, 1995[JP] | 7-234547 |
Current U.S. Class: | 370/218; 370/232; 370/517 |
Intern'l Class: | H04L 001/22; H04J 003/06 |
Field of Search: | 370/217-220,252,253,229,232-235,242,244,395,503,516,517 375/371,372 395/200.55,200.63,200.62 340/825.01 |
5237318 | Aug., 1993 | Auclair et al. | 340/825. |
5285441 | Feb., 1994 | Bansal et al. | 370/517. |
5301184 | Apr., 1994 | Uriu et al. | 370/219. |
5398235 | Mar., 1995 | Tsuzuki et al. | 370/219. |
5408463 | Apr., 1995 | Merchant et al. | 370/218. |
5475675 | Dec., 1995 | Kondo et al. | 370/219. |
5561661 | Oct., 1996 | Edmaier et al. | 370/517. |
Foreign Patent Documents | |||
4-104635 | Apr., 1992 | JP. | |
4-100451 | Apr., 1992 | JP. | |
4-130838 | May., 1992 | JP. | |
4-266241 | Sep., 1992 | JP. |